1. Field of the Invention
The present invention is directed to a vane-type fluid power converter, and more particularly, to a vane-type hydraulic motor having a spring button located between a vane and a spring to prevent the spring from coming into contact with the vane or with the end plate or housing.
2. Description of the Related Technology
It is known generally in the prior art to provide hydraulic motors and pumps having a rotor circumferentially surrounded by a stator, each of the rotor and stator exhibiting spring loaded vane elements protruding from slots in the surface thereof and having an outer edge in sliding contact with the opposing surface. Such motors and pumps can experience performance deterioration or catastrophic failure due to wear between the spring and vane element. When the rotor, vanes and springs rotate, the springs rub against the bottom of the vane and against the plate or housing adjacent to each side of the stator. As the spring rotates, it continues to rub on both the vane and the plate or housing. The continued rubbing causes spring wear which can cause the spring to break either on the face of its diameter where it touches the vane or along its length where it touches the plate or housing. When the spring breaks, the motor performance deteriorates, or a broken segment of the springs can wedge itself between the rotating or stationery components and cause catastrophic failure.
The spring wear between the spring and vane occurs because the vane slightly but continually vacillates within the vane slot within which it lies as fluid pressure is alternatingly applied to and released from the portion of the vane extending from the vane slot. This vacillation causes a milling and rubbing action to occur between the upper end of the spring and the bottom of the vane, thus causing wear on the upper portion of the spring which is in contact with the vane. Furthermore, the spring is trapped between a spring pocket in the rotor and the plate or housing. Compression of the spring causes the spring to buckle and rub on the stationary plate or housing as the rotor rotates. Such rubbing causes wear on the side of the spring that falls in contact with the stationary plate or housing.
For the foregoing reasons, there is a need for a vane-type fluid power converter wherein the spring is prevented from coming in contact with the vane and plate or housing, thus preventing spring wear.